Alternator identification (pics)

I got all set to take the (what I thought was) externally regulated alternator off and found that the one I got from NAPA looks awfully similar. Actually the only difference is the tabs are on top on the new one and on the back on the old one. So question #1 is are they both 10SI's? Question 2 is why would the regulator stayed on if the old one is in fact a 10SI? I found this article , http://www.hotrod.com/techarticles/marlan_davis_technical_advise/photo_22.html which explains the conversion a little differently than this one. http://www.acampora.com/HTM_Pages/Index_Pages/Farmall_Pages/12-Volt-Conversion.htm
My setup sure seems to look like that first link's setup but why use the regulator (external) at all? Aren't you doing the same thing? So why multipe ways?
Although it says 12SI the author explains it is the same for a 10SI.

In case nobody has noticed, I have managed to confuse the living hell out of myself. Sure wish I had never pressure washed the thing (the wire you see loose on the regulator came off due to a rusted out connection). The loose wire has me in fits as to whether I am overcharging the battery. It SEEMS fine but there is white powder around that I am taking for fluid boilover. The ammeter nbeedle stays just a touch over into the plus side. This just isn't my day for machinery...

Your first two pics is of a 10DN which is externally regulated.

The pic of the regulator looks like the one for the 10DN

The last two pics is of a 10SI which is internally regulated and in my opinion more desirable then the 10DN.

The alternator that is mounted on the tractor in the picture is a Delco "10DN" alternator, referring that is externally regulated. Now the new one purchased is a Self integrated alternator no longer needing the voltage regulator mounted on the side. Searching past posts you may find electrical diagrams on how to wire in the #1, #2, and Bat terminals into to your electrical circuit. #1 terminal keyed power, #2 goes to bat terminal and Bat terminal goes to either to voltage or ammeter.

Great!! So I was doing it right. The sameness through me for a loop. So I can just go ahead and go with the proceduers for the tractor that I was going to do. Thanks!!

You will need to throw that VR away and rewire the new alternator the correct way for it to work as it should. You will also need a light bulb or diode like the radio shack 276-1661 wired into the #1 plug wire going to the ignition switch
Hobby farm

The one on the tractor is an externally reg 10DN.

Rod

The externally regulated Delco seems to start charging at lower RPM than do the others. And the wiring harness is considerably different for the internally regulated alternators. I suggest just putting your present system in good working order rather than swapping to another type alternator.

(quoted from post at 04:44:08 07/24/08) The externally regulated Delco seems to start charging at lower RPM than do the others. And the wiring harness is considerably different for the internally regulated alternators. I suggest just putting your present system in good working order rather than swapping to another type alternator.

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The prolem with that is that the external regulator is toast. It would be easier to put it back how it was but I haven't had any luck finding out what regulator to get. I tried finding it out here but the recommendations were almost universal to go to a 10SI. Might as well since I have the part.

Get a regulator for a 1971 Chevrolet BelAire with 6 cylinder engine. No air conditioning, if they ask. It will work fine with your existing alternator.